Amazon CloudWatch has now added support for EC2 Action in Alarms for using the Service Linked Actions

Amazon CloudWatch has now added support for utilizing the Service Linked Roles to deploy CloudWatch Alarms with the Elastic Cloud Compute Actions. A Service-linked Role is a typical type of IAM role that is connected directly to the CloudWatch. The Service-linked roles are pre-defined by the Amazon CloudWatch and consist all the permissions that the service needs to call other Amazon Web Service on the user's behalf. The service linked role in the Amazon CloudWatch sets up the CloudWatch Alarms that reboot, stop and terminate the Amazon Elastic Cloud Compute instance easily because you will not require to manually add the necessary permissions.